1 . Determination and optimism are ________ it takes to conquer your fear and accomplish your goal. (用适当的词填空)

2 . As we all know, reading classics is of great importance to us. This is ________________ it can not only improve our studies but also enrich our everyday life. (用适当的词填空)

3 . In the novel, this is___________Jia Baoyu and his female cousins lived. （用适当的词填空）

4 . What worries us most is ________ let out the secret. (用适当的词填空)

5 . The best part of the art work is ________ people can think of something of their own.(用适当的词填空)

6 . This is ________ I went there by train. (用适当的词填空)

7 . What worries me most is ________ we make him feel at home. (用适当的词填空)

8 . Taking a year off from school to travel abroad is ________ is generally called a gap year. (用适当的词填空)

9 . He is not the best candidate for the position.So the problem is ________we can get to replace him.（用适当的词填空）

10 . How could we live without the Internet? That's ________ most of us keep in touch with each other. （用适当的词填空）